1. Field of the Invention
The present invention relates to a pattern forming method, for example, to a pattern forming method which is performed in a lithography process for manufacturing a semiconductor device.
2. Background Art
A pattern forming method using a water-soluble resist pattern shrink material of an acid cross linking type has had a problem that, in a peeling step for removing the shrink material, photosensitizers acting as photo acid generators in a resist layer are deposited on a resist pattern after a spin-dry step to cause defects.
In general, the surface of the resist pattern after a shrink process is hydrophobic. On the hydrophobic surface, a watermark is easily generated, which causes defects.
A method for suppressing defects by using, for example, an activator as a special rinse liquid to the shrink material can be considered. However, in this case, it is necessary to provide a dedicated line for supplying the special rinse liquid, which increases a cost. Further, a rinsing process takes long time, which lowers a throughput. Therefore, a method for reducing defects without using the special rinse liquid has been desired.
An example of a conventional pattern forming method is disclosed in JP-A H10-73927 (KOKAI).